1、 Filter leak detection

For the high-efficiency filter installed at the end of air supply and exhaust, the scanning method shall be used for filter installation frame and full section leakage detection. There are two scanning methods: leak detector method (photometer method) and particle counter method with a minimum sampling amount of 1l / min. For ultra-high efficiency filter, there are two scanning methods: condensation nodule counter method and laser particle counter method.

1. Leak detector method

(1) The leakage detection filter must have measured the air volume and operate between 80% ~ 120% of the design wind speed.

(2) When multiple filters are installed on the same air supply surface, the method of exposing only one filter at a time should be used for measurement if the structure allows.

(3) When several or all filters must be exposed to aerosol at the same time, in order to evenly mix all filters, aerosol for leak detection should be introduced into the suction end of the fan or the branch pipe in front of these filters, and the concentration on the windward side should be measured immediately in front of the tested filter.

(4) For the high efficiency filter, when the leak detection instrument is logarithmic scale, the aerosol concentration on the upwind side shall exceed 104 times the minimum scale of the instrument; When the leak detector is of linear scale, the aerosol concentration on the upwind side shall reach 80 ~ 100 μ ｇ/L。 The leakage detection instrument shall have 0.001 ~ 100 μ Measurement range of g / L.

2. Particle counter leak detection

(1) The tested filter must have measured the air volume and operate between 80% ~ 120% of the design wind speed.

(2) Measure the number of particles of atmospheric dust on the windward side of the tested high-efficiency filter to be greater than or equal to 0.5 μ M particle shall prevail, and its concentration must be greater than or equal to 0.1 if ultra-high efficiency filter is detected μ M particles, whose concentration must be greater than or equal to

(3) If the concentration on the windward side does not meet the above provisions, unfiltered air shall be introduced. If it does not meet the provisions, particle counter method and condensate counter method shall not be used for leak detection.

3. During leak detection, place the sampling port 2 ~ 3cm away from the surface of the tested filter, move it at the speed of 5 ~ 20mm / s, and scan the whole section of the tested filter, head rubber and installation frame.

2、 Detection of air volume and wind speed

1. The detection of air volume and wind speed must be carried out first, and all effects of purified air conditioning must be obtained under the designed air volume and wind speed.

2. Before air volume detection, it is necessary to check whether the fan operates normally, whether all components in the system are installed correctly and whether there are obstacles (such as whether the filter is blocked or blocked). All valves should be fixed at a certain opening position, and the size of the measured air outlet and air duct must be measured.

3. For the unidirectional flow (laminar flow) clean room, the air supply volume is determined by the product of the average wind speed of the room section and the cross-sectional area, in which the measured section of the vertical unidirectional flow (laminar flow) clean room is the horizontal section 0.8m away from the ground; The horizontal unidirectional flow (laminar flow) clean room takes a vertical section 0.5m away from the air supply surface. The spacing of measuring points on the section shall not be greater than 2m, and the number of measuring points shall not be less than 10, which shall be evenly arranged. Hot bulb anemometer for instrument.

4. For the turbulent flow clean room, the air supply volume shall be determined by the air outlet method or air duct method. See Item 6, 7 and 8 respectively.

5. For the air outlet without filter, the method in Appendix I of the current national standard code for construction and acceptance of ventilation and air conditioning engineering (gbj243) can be implemented.

6. For the tuyere equipped with filter, the auxiliary air duct can be selected according to the tuyere form, that is, the straight pipe section with the same section as the tuyere and the length equal to twice the side length of the tuyere is made of hard plate, which is connected to the outside of the filter tuyere. The measuring points are evenly arranged on the outlet plane of the auxiliary air duct according to the minimum number of measuring points, and the wind speed of each point is measured with a hot ball anemometer. The air volume is determined by multiplying the average wind speed at the section of the air outlet by the net section area of the air outlet.

               

         

Suzhou Pharma Machinery Co.,Ltd.

2022/04/29

David